Whether you believe it's coming in a rain of fire, radioactive Sushi Cats, or a sea of zombies and their perplexingly sexy survivors, one thing's for sure... we're obsessed with the end of the world. There's something about the concept of good ol' post-apocalyptica that sparks the imagination, and people have been making all sorts of media about it for... well, since forever, practically.

Louis-Simon Ménard, or Louissi as he's been known to millions of players, originally set out to make BunkerSIM with his friend Francis Beausoleil in Flash like all of his previous titles. What was intended to be a small survival simulation minigame quickly grew in size and complexity, however, and it soon became apparent that the game would need something bigger and beefier if it was to live up to its creator's (and growing fanbase's) expectation.

And so, following a successful Steam Greenlight campaign, Louissi made the decision to port the game to Unity and continue its development there. "Unity is so fast and unlimited," the team says. While they've always wanted to experiment more with visuals, they've had to keep things restricted in the past for Flash's performance. Think of it like that kid your parents made you hang out with whose bike only really worked downhill. Where in the past they developed tricks to get around the previous platform's limitations, Unity has opened everything up. You know that scene in Wizard of Oz where everything goes from black and white to glorious technicolour? It's exactly like that, even down to the pigtails.

"On my side, Flash is still very present - even with all the recent “Flash is Dead” debacle," said Francis. "Although a lot of the pixel art is made with Photoshop, we still use Flash as a production and animation tool in the pipeline. Making pixel art has been a real throwback for me as I’ve been doing 3D and 2D vector work for all my professional career. Being a child (or rather product?) of the 80s, pixel art was THE only way to make computer graphics for a while so I’ve of course tried my hand at it numerous times. It’s really been an eye opener to create all those assets. You realize that back then, they did it out of hair spray and neon pixels and you appreciate it a whole lot more.

"I’ve had some experience in Unity but only for 3D, so it’s been a blast seeing what Louissi can accomplish with our 2D assets!" he went on. "We can’t wait to add more atmosphere to the underground part of the game. From shaders to lighting effects, we’re going to be able to push the pixel art aesthetic to a level of quality unattainable with Flash."

As work has begun moving BunkerSIM to its new home on Unity, the team told me they were surprised at how easy it was to add lighting and effects. Bloom for fog, animated and flickering signs, underground lights that add depth to make the art "pop"... combine all that with a gorgeous day/night and weather system that takes full advantage of the colour grading, and you have a game that looks drastically different from its original form. Like that recent remake of that popular TV show from your childhood that you were excited for, only, y'know... not sucky.

"The first version of Bunker Sim was made in Flash," Louissi says. "It was around 75% done. Complete enough for a 20 minute demo at PAX East this year. I had a long journey with Flash; I've been making games on it since 2003. It has always been reliable and fast for small projects. Unfortunately, on larger projects like Bunker Sim, it struggled to stay efficient. I learned tricks along the way to keep the framerate up, but it was clear I was asking too much of it. While Haxe and other things exist and work, I didn’t want to learn yet another trick to make Flash useable for me again. Unity felt, and still feels, like the best option. Especially distribution-wise.

"It took a couple months to get up to speed," Louissi continues. "I had never used the new UI system, so I had to experiment with it. It does some things very well, like multi-resolution support and navigation, but I would have hoped for more widgets from the get go, as the ones included are pretty much the bare minimum.

"So far the project has been a lot of engine work. There is a lot that goes on under the hood of a game. Usually I would use the same game wrapper for every game but this time I had to make a new one. The good news is that all the art from the first version of the game will be transferred and upgraded. We are also adding a lot of features thanks to the new performance gain."

Those features run the gamut from adding extra depth and complexity, to the ability to mod the game itself. That all-important game wrapper is built, but the sprite browser is what may make a lot of players perk up and take notice. "The players will be able to add new items, resource types, hairstyles, clothes, etc... You get the point," says Louissi. "I’m a big fan of user-generated content and I think it can do wonders for the longevity of a game."

You know what that means. Sushi Catpocalypse can be a reality, if you only dream it so.

Beyond that, the game's overworld is mostly complete, including an intelligent world generator. As planned, it'll craft maps "realistically", generating dense urban sprawls in the center that give way to suburbs, then sparse farmland, and the rural wilds and beyond. This logical progression should help to immerse players in the game, but Louissi also talked excitedly about the variety of sprites available at character creation. Allowing for different genders and skin tones is a first, and Louissi says he's happy to have a multi-cultural game everybody can create themselves in. All running in silky-smooth 60FPS even in the editor. Righteous.

"Now that I’m done with the player profiles, menu system, data management and all that super important but super boring stuff, I can move on to the gameplay itself," Louissi says with no small amount of relief. "Logically, I started with the world map, which will contain everything else later. Francis has been creating a lot of new art and I think it just looks gorgeous. I kinda want to make a SimCity game now. Maybe one day. I’ve been playing around with Unity’s color correction and shaders to make the sprites stand out and shine and I’m surprised how easy it is. You can expect gloomy rainy nights!"

While BunkerSIM still has a ways to go, it's clear it's grown a lot from its initial scale. Certain other notorious game releases that rhyme with Shmallshout Smelter that came out after BunkerSIM was originally announced may seem similar, the more the team works, the clearer it becomes that BunkerSIM is going to be its own beast. Expect more details as we keep you updated in the month to come. They say war never changes. But when it comes to post-apocalyptic indie games, the sky's the limit.

For more on BunkerSIM, follow Louissi on Twitter and his official blog, and follow Armor Games on Facebook and Twitter for sneak peeks and teasers.